The load-handling devices may be used to raise or lower loads and will typically provide a mechanical advantage to the user to facilitate the handling of loads. One of the most common forms of load handling device with a mechanical advantage is a pulley arrangement in which a pair of pulleys are interconnected by a rope. One of the pulleys is connected to a fixed support and the other connected to the load and the entrainment of the rope around the pulleys enables the load to be raised or lowered. The mechanical advantage obtained will depend upon the number of pulleys used in the train.
One application for such a load-handling device is for use with rescue teams in which it is frequently necessary to lift or lower an injured person. In those circumstances a pulley system would be utilized to give the necessary mechanical advantage to the rescuer. With a conventional arrangement of pulley system it is necessary to control the lowering of the load by maintaining a restraining force that is the same as the force required to lift the load. In certain circumstances this may be onerous, particularly where the rescue is occurring in a hazardous environment.
It is therefore an object of the present invention to provide a load-handling device in which the above disadvantages are obviated or mitigated.